Analysis of mitochondrial function is central to the study of intracellular energy metabolism, mechanisms of cell death and pathophysiology of a variety of human diseases, including myopathies, neurodegenerative diseases and cancer. However, important properties of mitochondria differ in vivo and in vitro. Here, we describe a protocol for the analysis of… (More)

The kinetics of in vivo regulation of mitochondrial respiration by ADP was studied in rat heart, slow-twitch skeletal muscle (soleus) and fast-twitch skeletal muscle (gastrocnemius, plantaris, quadriceps and tibialis anterior) by means of saponin-skinned fibres. Mitochondrial respiratory parameters were determined in the absence and presence of creatine (20… (More)

Relative diffusivities of ADP and creatine in cardiomyocytes were studied. The isolated rat cardiomyocytes were lysed with saponin (40 micrograms/ml) to perforate or completely disrupt sarcolemma that was evidenced by leakage of 80-100% lactate dehydrogenase. In these cardiomyocytes mitochondria were used as 'enzymatic probes' to determine the average local… (More)

The conditions of treatment of human skeletal muscle fibers from M. vastus lateralis with saponin were optimized to achieve complete permeabilization of cell membrane at intact mitochondrial oxidative phosphorylation. After 30 min of incubation with saponin all lactate dehydrogenase, 50% of creatine kinase, 30% of adenylate kinase and less than 20% of… (More)

To define more clearly the interactions between mitochondrial creatine kinase and the adenine nucleotide translocase, the outer membrane of rat heart mitochondria was removed by digitonin, producing an inner membrane-matrix (mitoplast) preparation. This mitoplast fracton was well-coupled and contained a high specific activity of mitochondrial creatine… (More)

Possible reasons for retarded intracellular diffusion of ADP were investigated. The isolated skinned cardiac fibers were used to study apparent kinetic parameters for externally added ADP in control of mitochondrial respiration. Participation of myosin-ATPase in binding of ADP within cells as it was supposed earlier (Saks, V.A., Belikova, Yu.O. and… (More)

The current problems of regulation of myocardial energy metabolism and oxidative phosphorylation in vivo are considered. With this purpose, retarded diffusion of ADP in cardiomyocytes was studied by analysis of elevated apparent Km for this substrate in regulation of respiration of saponin-skinned cardiac fibers, as compared to isolated mitochondria.… (More)

Respiratory parameters of cardiac mitochondria were determined in the bundles of cardiac fibers skinned by using saponin that specifically removed sarcolemma, but left intracellular structures intact. In the assay medium which simulated the ion composition of cardiac cytoplasm maximal value of state 3 oxygen consumption per mol cytochromes aa3 was close to… (More)

Chemically skinned (by treatment with saponin, 40 micrograms/ml) isolated cardiomyocytes were used to study the intracellular diffusion of ADP and creatine (Cr). Stimulation of respiration was studied in these cardiomyocytes without intact sarcolemma and in isolated heart mitochondrial by addition of ADP and Cr in the presence of 0.2 mM ATP (via… (More)

In skeletal muscle homogenates of 14 patients with sporadic amyotrophic lateral sclerosis, an approximately twofold lower specific activity of NADH:CoQ oxidoreductase in comparison to an age matched control group (n=28) was detected. This finding was confirmed by a detailed analysis of mitochondrial oxidative phosphorylation in skeletal muscle using… (More)